APRIL 2015
Protecting the ACT from invasive weeds: highlights from 2009 to 2014
Weeds are plants growing where they are not wanted
that can have major economic, environmental and social
impacts. There are two main types of weeds including
weeds of disturbed areas and invasive weeds (see Box 1).
Highlights of the first five years of the strategy, from
2009 to 2014, include:
Invasive weeds reduce primary industries productivity
and interfere with the ecological and other functions
of waterways. They damage nature conservation
assets and values, impact on biodiversity by competing
with native plants and degrading habitat, and are a
significant threat to many of the ACT’s threatened
species and ecological communities.
• enhanced capacity to detect, contain and eradicate
new weed incursions
The costs of preventing and controlling invasive weeds and
the lost asset value can be significant for land managers,
including farmers and government. The ACT Government
therefore conducts annual invasive weed control operations
(Figure 1) and supports complementary control efforts by
rural landholders and community groups.
This work is guided by the ACT Weeds Strategy
2009–2019 (the strategy), which aims to reduce the
impact of weeds on the environment, the economy,
human health and amenity. The strategy recognises
that control of higher-risk invasive weeds is most
effective when included in sustainable natural resource
and environmental management using a whole of
community, industry and government approach.
Figure 1 – An incursion of Madagascan Fireweed, a highly
invasive Weed of National Significance, has recently been
contained in the ACT through emergency response procedures
• improved risk assessment, delivery and reporting of
government weed control operations
• increased control of Weeds of National Significance
(WoNS) and several highly invasive grasses
• adoption of innovative approaches to weed control and
• greater collaboration between local and regional
government, landholder and community groups
Box 1 – Weeds of disturbed areas and invasive weeds
Weeds of disturbed areas are weeds that take
advantage of disturbed conditions to spread.
Disturbed areas include gardens, lawns, footpaths,
nature strips on roadways, playgrounds and some
waterways. Weeds of disturbed areas are often
annual grasses and herbs that take on an ‘untidy’ look
and these are what many people think of as weeds.
Invasive weeds are introduced plants that
spread aggressively and cause damage to the
environment, the economy and human or animal
health. Impacts include smothering native
vegetation, reducing farm income, preventing use
of recreational areas, triggering allergic reactions
and poisoning grazing animals. Most invasive
weeds are introduced plants from overseas (e.g.
Blackberry from Europe, Serrated Tussock from
South America). Some are native plants that have
been introduced to an area from outside of their
natural range (e.g. Cootamundra Wattle). Invasive
weeds are sometimes called invasive plants.
Invasive weeds that occur in native vegetation
are also called environmental weeds. Similarly,
invasive weeds in agricultural areas are also called
agricultural weeds. Invasive weeds, as opposed
to weeds of disturbed areas, are the focus of the
annual Invasive Weeds Operations Plan (iWOP;
see ‘A new weed risk management approach’
below), because they have significant impacts on
the environment, agriculture, people and animals.
environment.act.gov.au
Background
The ACT Weeds Strategy 2009–19 established five best
practice principles that are consistent with the Australian
Weeds Strategy:
1. Weed management is essential for the sustainable
management of natural resources and the
environment and for social well-being, and requires an
integrated, community-wide approach.
2. Prevention and early intervention are the most costeffective approaches that can be deployed against weeds.
3. Successful weed management requires a coordinated
approach involving all levels of government in
partnership with industry, landholders and community.
4. All land managers have a duty of care to manage
weeds on their land.
5. Community interests shall be protected from weeds by
appropriate legislation.
A new weed risk management approach
Through the strategy, the ACT Government has improved
its capacity to target the highest priority species and
assets (such as nature parks) and obtain a greater return
on weed control investment.
This has been largely achieved by adapting the NSW
Weed Risk Management System for ACT data (Figure 2).
This system assigns priority to weeds based on their risk
and feasibility of control, and provides guidance on the
most appropriate approach to manage the weeds.
Weed risk assessments help the ACT Government
categorise declared pest plants in the ACT and prepare
an annual Invasive Weeds Operations Plan (iWOP, Figure
3). The annual iWOP summarises expenditure and
documents which species will be targeted for control at
specific locations within the ACT’s parks and reserves,
urban areas and rural roadsides. For 2014–15, nearly
25% of operations will be joint control projects with
neighbouring rural landholders.
Each year, areas where invasive weed control operations
were completed are mapped and included in the ACT Parks
and Conservation Weeds Atlas. This ensures invasive weed
control locations are permanently recorded and helps with
follow-up control to protect the ACT Government’s initial
investment at the site. The map below (Figure 4) is an
example from the ACT Parks and Conservation Weeds Atlas.
The map shows areas where weed control was undertaken
for a range of species in selected Canberra Nature Park
reserves and surrounding suburbs.
Figure 2 – ACT adaptation of the NSW DPI Weed Risk Management System
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Figure 3 – Annual Invasive Weeds Operations Plan
Figure 4 – A sample map from the ACT Parks and Conservation Weeds Atlas.
www.act.gov.au3
Improving weed detection, containment
and eradication
The most cost effective way to control invasive weeds
is to prevent them entering, becoming established
and spreading across the ACT. Since 2009, the ACT
Government has eradicated incursions of Mexican
Feathergrass, African Fountain Grass and Artichoke
Thistle. Seven other weed incursions have been
contained including Madagascan Fireweed, a high risk
Weed of National Significance. Recent responses to
Madagascan Fireweed incursions have demonstrated
the effectiveness of the ACT’s biosecurity emergency
response procedures.
The information is used by the government to identify
incursions early and triggers ongoing control efforts
through automatic alerts to government for selected
high risk species.
http://root.ala.org.au/bdrs-core/act-esdd/home.htm
ACT Parks and Conservation staff and contractors
are also using the off-line Memory-Map Smartphone
applications for mapping weed control areas and
uploading this data to the ACT Parks and Conservation
Weeds Atlas. A presentation of this work was made at
the 19th Australasian Weeds Conference.
Innovative ways to control weeds
A potential threat analysis has identified weed incursion
pathways and provided risk assessments for 20 high priority
weeds occurring in the ACT and in neighbouring NSW.
The Territory and Municipal Services Directorate has
introduced some innovative methods for reaching weeds
in relatively inaccessible places. These include:
This analysis has been used for the ACT adaptation of
the NSW Weed Risk Management System, which is an
important part of the annual iWOP (Figures 2 and 3).
• abseiling down the Molonglo Gorge to spot spray the
highly invasive Prickly Pear (Figure 5)
The new ACT and Southern Tablelands Weed Spotter
website and associated iPhone and Android mobile
applications enables community members to record the
location of new weed incursions and established weed
populations, and record weed control efforts in the
CSIRO Atlas of Living Australia.
• use of an eight wheel drive amphibious vehicle, called
Argo 800, equipped with a 200 litre tank of herbicide
to tackle Blackberry and Tree of Heaven in the rough
terrain along the Murrumbidgee River and
• trialling an unmanned remote controlled helicopter
equipped with tanks of herbicide to control Blackberry
along the Murrumbidgee River.
Figure 5 – Abseiling in the Molonglo Gorge to control Prickly Pear, a Weed of National Significance
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Action on Weeds of National Significance
Weeds of National Significance (WoNS) are high priority
species for control based on their invasiveness, adverse
environmental, economic and social impacts, and
potential for spread across multiple states. From 2009
to 2014, the ACT Government has reduced the threat
posed by WoNS through:
• targeting African Boxthorn, Blackberry, Broom, Gorse,
Chilean Needle Grass, Madagascan Fireweed, Serrated
Tussock and Willows in annual control operations
• declaring 32 WoNS as ‘Prohibited’ pest plants under
the Pest Plants and Animals Act 2005 to meet a
national agreement to prevent their sale and supply
• completing risk assessments for 13 WoNS species
• developing a Madagascan Fireweed Pest Plant
Management Plan (a notifiable instrument under the
Pest Plants and Animals Act 2005) that sets out the
requirements for control in the ACT and allows for
enforcement in the event of non-compliance
• drafting a Serrated Tussock Pest Plant Management Plan
• releasing Scotch Broom Gall Mite for the biological
control of Broom species and
• delivering a Caring for our Country-funded, $300,000
devolved grants program targeting control of WoNS
by rural landholders and community groups (control
activities were undertaken on over 33,000 hectares in
the ACT).
Controlling African Love Grass
African Love Grass is an introduced, low-quality grass
that is highly competitive, particularly in infertile
soils (Figure 6). It excludes other pasture species and
significantly reduces stock carrying capacity.
Figure 6 – An infestation of African Love Grass
An ACT Environment Grant helped an ACT rural landholder
control African Love Grass using a combination of
herbicide application and improved soil fertility to
suppress widespread infestations, thereby increasing
production of native and introduced pasture species
including Weeping Grass and clovers.
This landholder’s work adds to a suite of control methods
being adopted by ACT rural landholders (e.g. pasture
establishment and vigilant control). These control
methods are being promoted through field days and
activities undertaken through the ACT Regional Landcare
Facilitator program and the work of catchment groups.
ACT Weeds Forum proves popular
An ACT Weeds Forum in 2012 brought together 67
ACT and regional government and non-government
stakeholders to explore fresh approaches to reducing
the prevalence and spread of existing weeds, and the
incursion of new species in a changing climate. The
forum generated a suite of recommendations for
improving weed management in the ACT, including the
development of the ACT and Southern Tablelands Weed
Spotter website.
This highly successful forum will become a triennial
event, with future forums scheduled for 2015 and 2018.
Strategic priorities for 2015-19
Over the next five years the ACT Government will aim to
address the following strategic priorities, including:
• improved monitoring and evaluation of invasive
weed control operations to continually improve their
effectiveness and return on investment
• coordinated control of Serrated Tussock threatening
Namadgi National Park
• better surveillance for high-risk invasive weeds such
as Orange and Mouse-ear Hawkweed through seeking
assistance from key stakeholder groups
• developing species-specific response plans to improve
rapid response times and eradication success for new
weed incursions
• undertaking a review of the plant species
recommended for use as street trees and in urban
landscape plantings
• improved compliance with vehicle hygiene and
mowing protocols to reduce the spread of invasive
grasses such as African Love Grass
• maintaining and improving support for community
groups undertaking weed control efforts
• reviewing the Pest Plants and Animals Act 2005 so that
responsibilities for controlling weeds are clearer.
www.act.gov.au5